EDIT: Oh, it's a Google Groups response:
We're writing to let you know that the group you tried to contact (careers) may not exist, or you may not have permission to post messages to the group. A few more details on why you weren't able to post:
* You might have spelled or formatted the group name incorrectly.
* The owner of the group may have removed this group.
* You may need to join the group before receiving permission to post.
* This group may not be open to posting.